I just don't get it. I was talking to someone on 40 meters recently, who wanted to buy a ranger and put it into an amplifier, because the ranger was small in size??? The ranger plus the amp is smaller than a valiant?
Another guy wanted to put his valiant into an amp running 811A tubes I think, I forget. After working it out, running the tubes flat out would give him 200 watts of carrier, a 50 watt increase in output power, with all the critical amp adjustments, and the excessive power consumption. I told the guy, a pair of 811a/812a tubes (both work fine) in class C plate modulated service gives about 300 watts out without pushing them hard. Mod transformers are not impossible to find, and loads of tubes make a good moderate power class C finals, 811A tubes from Russia (if you want new ones) are about $20.00 each? for modulators. 813, 811a, or 812a, kt88/kt90 tubes in push pull make fine modulators, a 813, 811a, 812a, 4-124, 4-250-400, pair of 4d32 tubes will do as the RF final. A valiant at 150 watts out is fine for 40 meters, as is the Johnson 500, various globe king stuff (with mods), and even a 32v3 or dx100 and other 100 watt transmitters will do fine on 40 meter AM. I would think if one were to shop around, you could come up with a nice rig for well under the cost of some transmitter and a big monster amp. Or build something that puts out 100 to 300 watts of AM, even if it just runs on 40 meters. Seems amps are very common anymore, lots of guys seem to be running some small crappy radio into all sorts of amplifiers, rice boxes, dx60, globe scouts, rangers, etc. To me, it just looks like a giant inefficient pain in the butt, tuning up all sorts of things till its just right, and beating the hell out of an amplifier to get 200 watts out, instead of running something like a valiant. You could not tell the difference at the other end between 150 and 200 watts. All amps ADD distortion to a signal, so no improvement there. Most amps have noisy fans, and you can almost always tell the people running them, by that loud blower noise in their audio. That is one of the really nice things about my 812A rig, not a single blower or fan in it, no noise when its in use at all. 275 to 300 watts out of a pair of wimpy 812a tubes! What does a good amp cost, one that runs a pair of 3-500Z tubes and a rugged power supply, $2500.00? I think for $2500.00 you could come up with a nice valiant, 500, 30k-1, 32v3, t368, globe king 400, or build something nice. But it seems like the in thing to do is to buy a clean ranger for $600.00 and run it into an amp... Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Jim Candela > Sent: Wednesday, December 24, 2003 9:14 AM > To: [email protected] > Subject: Re: [AMRadio] need 2 watt non inductive resistors > > > Tony, > > One other thing. A valiant can put out 150 watts of AM > carrier, and a T-Bolt should be able to put out 400 watts > when the 4-400's are running flat out at maximum plate > dissipation (back to that 33% efficiency again of AM linear > amps). If you back off the T-Bolt to ease the burden on the > tubes, then maybe 300 watts output. So this approach gives > you 3 db power boost above the Valiant. Consider that even if > you de-tune the valiant to 75 watts out, you still need to > get down somewhere into single digit watts to drive the > T-Bolt. Looks like a 10 db, or more pad is required. Is all > this trouble worth it to you? An AM rig with a single 6146, > or 2e26 in the output may be a better approach to drive the > T-Bolt. Good luck with your project.. > > Jim > > > "Anthony W. DePrato" <[EMAIL PROTECTED]> wrote: > i need to build two pads and will need the following > resistors all 2 watt > 10 - 1200 ohm > 4 - 470 ohm > 10 - 4700 ohm > 12 - 220 ohm > 4 - 68 ohm > 12 - 820 ohm > > tried mouser digikey and aes. anyone have any ideals where i > might find > them or if the new type resistors that they carry will work. > they have to > be non inductive . dropping the power out of my valiant and other > transmitters to drive my thunderbolt. > thanks 73 Tony > > QBE ZUT DE WA4JQS SK > > --- StripMime Report -- processed MIME parts --- > multipart/alternative > text/plain (text body -- kept) > text/html > The reason this message is shown is because the post was in HTML > or had an attachment. Attachments are not allowed. To learn how > to post in Plain-Text go to: http://www.expita.com/nomime.html --- > _______________________________________________ > AMRadio mailing list > [email protected] > http://mailman.qth.net/mailman/listinfo/amradio > > --- StripMime Report -- processed MIME parts --- > multipart/alternative > text/plain (text body -- kept) > text/html > The reason this message is shown is because the post was in HTML > or had an attachment. Attachments are not allowed. To learn how > to post in Plain-Text go to: http://www.expita.com/nomime.html --- > _______________________________________________ > AMRadio mailing list > [email protected] > http://mailman.qth.net/mailman/listinfo/amradio
